function PDE = process_pde_2d(exmple_index)
switch exmple_index
    case 1
        PDE.index = exmple_index;
        PDE.err = true;
        PDE.u = @(x,y,t) exp(x+y+t);
        PDE.dudx = @(x,y,t) exp(x+y+t);
        PDE.dudy = @(x,y,t) exp(x+y+t);
        PDE.cor = @(x,y,t) 2*ones(size(x));
        PDE.f = @(x,y,t) -3*exp(x+y+t);
        PDE.domain = [0, 2, 0, 1, 0, 1];
        PDE.bdary = [0, 0, 0, 0];
    otherwise
        error("Invalid PDE exmple_index");
end
if PDE.err
    fprintf("PDE example: %d (有解析解的问题)\n", exmple_index);
else
    fprintf("PDE example: %d (Benchmark)\n", exmple_index);
end
fprintf("PDE domain: xmin,xmax,ymin,ymax,tmin,tmax\n");
disp(PDE.domain);
fprintf("PDE boundary: bottom,right,top,left (0=Dirichlet,1=Neumann,2=Robin)\n");
disp(PDE.bdary);
end